/* Copyright (c) 2020 XEPIC Corporation Limited */
/*
 * Copyright (c) 2008-2018 Stephen Williams (steve@icarus.com)
 *
 *    This source code is free software; you can redistribute it
 *    and/or modify it in source code form under the terms of the GNU
 *    General Public License as published by the Free Software
 *    Foundation; either version 2 of the License, or (at your option)
 *    any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
 * USA.
 */

#include <assert.h>
#include <stdlib.h>
#include <string.h>

#include "vvp_priv.h"

static void draw_tran_island(ivl_island_t island) {
  fprintf(vvp_out, "I%p .island tran;\n", island);
  ivl_island_flag_set(island, 0, 1);
}

void draw_switch_in_scope(ivl_switch_t sw) {
  ivl_island_t island;
  ivl_nexus_t nex_a, nex_b, enable;
  const char *str_a, *str_b, *str_e;

  ivl_expr_t rise_exp = ivl_switch_delay(sw, 0);
  ivl_expr_t fall_exp = ivl_switch_delay(sw, 1);
  ivl_expr_t decay_exp = ivl_switch_delay(sw, 2);

  island = ivl_switch_island(sw);
  if (ivl_island_flag_test(island, 0) == 0) draw_tran_island(island);

  nex_a = ivl_switch_a(sw);
  assert(nex_a);
  str_a = draw_island_net_input(island, nex_a);

  nex_b = ivl_switch_b(sw);
  assert(nex_b);
  str_b = draw_island_net_input(island, nex_b);

  enable = ivl_switch_enable(sw);
  str_e = 0;
  char str_e_buf[4 + 2 * sizeof(void*)];

  if (enable && rise_exp) {
    /* If the enable has a delay, then generate a .delay
       node to delay the input by the specified amount. Do
       the delay outside of the island so that the island
       processing doesn't have to deal with it. */
    const char* raw = draw_net_input(enable);

    draw_delay(sw, 1, raw, rise_exp, fall_exp, decay_exp);

    snprintf(str_e_buf, sizeof str_e_buf, "p%p", sw);
    str_e = str_e_buf;

    fprintf(vvp_out, "%s .import I%p, L_%p;\n", str_e, island, sw);

  } else if (enable) {
    str_e = draw_island_net_input(island, enable);
  }

  switch (ivl_switch_type(sw)) {
    case IVL_SW_RTRAN:
      fprintf(vvp_out, " .rtran");
      break;
    case IVL_SW_RTRANIF0:
      fprintf(vvp_out, " .rtranif0");
      break;
    case IVL_SW_RTRANIF1:
      fprintf(vvp_out, " .rtranif1");
      break;
    case IVL_SW_TRAN:
      fprintf(vvp_out, " .tran");
      break;
    case IVL_SW_TRANIF0:
      fprintf(vvp_out, " .tranif0");
      break;
    case IVL_SW_TRANIF1:
      fprintf(vvp_out, " .tranif1");
      break;
    case IVL_SW_TRAN_VP:
      fprintf(vvp_out, " .tranvp %u %u %u,", ivl_switch_width(sw),
              ivl_switch_part(sw), ivl_switch_offset(sw));
      break;

    default:
      fprintf(stderr, "%s:%u: tgt-vvp error: unrecognised switch type.\n",
              ivl_switch_file(sw), ivl_switch_lineno(sw));
      vvp_errors += 1;
      return;
  }

  fprintf(vvp_out, " I%p, %s %s", island, str_a, str_b);
  if (enable) {
    fprintf(vvp_out, ", %s", str_e);
  }
  fprintf(vvp_out, ";\n");
}
